Define the Elevation of boiling point

Explanation

(i) The boiling point of a liquid is the temperature at which its vapour pressure becomes equal to the atmospheric pressure.
(ii) When a non-volatile solute is added to pure solvent at its boiling point, the vapour pressure of the solution is lowered below 1 atm. To bring the vapour pressure again to 1 atm, the temperature of the solution has to be increased.
(iii) As a result, the solution boils at a higher temperature `(T_(b))` then the boiling point of pure solvent `(T _(b) ^(@)).` This increase in the boiling point is known as welection of boiling point.